Zoo officials were at pains to point out that the snakes could not have entered the city’s sewer system, nor are they venomous: probably points one and two on the public’s escaped snake panic card.

Having snake-shaped tunnels littered around the vivarium might seem a bit of a blunder on the part of the zoo’s designers, but Cathy Gaviller, Calgary zoo’s director of conservation, education and research, laid the blame squarely at the door of the Human Error department:

“A normal procedure that was put in place seven years ago when we opened the building wasn’t followed,” she frowned.